The Rover P4 series was a group of saloon automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s produced from 1949 through to 1964 designed by Gordon Bashford

Gordon Bashford

Gordon Dennis Bashford was a British car design engineer. Bashford played a significant part in the design of most post-war Rover cars, including the Land Rover and the Range Rover.-Career:...

. The P4 designation is factory terminology for the group of cars and was not in day-to-day use by ordinary owners, who would have said simply that they had a "Rover 90" and so on.

The P4 was also the basis of the short lived Marauder

Marauder Cars

thumb|right|270px|1951 Marauder TourerMarauder Cars was a British car company founded by Rover engineers George Mackie and Peter Wilks. Peter Wilks and George Mackie left the Rover Company in 1950 to form Wilks, Mackie and Company to exploit their idea of a two-seater sports car based on the new...

 car.
The cars used a Rover engine in 4 or 6-cylinder form which came from the 1948 P3

Rover P3

The Rover P3 car produced by the Rover company in 1948 and 1949 was very much an interim model.For the post-war market Rover had a new engine that had been in preparation since the late 1930s with overhead inlet and side exhaust valves. It was made in two version for the car, the "60" had a...

 and had overhead valve

Overhead valve

An overhead valve engine, also informally called pushrod engine or I-head engine, is a type of piston engine that places the camshaft within the cylinder block , and uses pushrods or rods to actuate rocker arms above the cylinder...

s for inlet and side valves for exhaust

Exhaust manifold

In automotive engineering, an exhaust manifold collects the exhaust gases from multiple cylinders into one pipe. The word manifold comes from the Old English word manigfeald and refers to the folding together of multiple inputs and outputs.In contrast, an inlet manifold is the part of an engine...

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